Prevalence of chlamydiae in dairy cattle herds and factors contributing to the spread of infections.

Introduction: Different Chlamydia species affect cattle and contribute to economic losses. One of them, C. pecorum, is a globally endemic livestock pathogen. Despite its endemicity, prevalence data from Poland have so far been limited. The present study aimed to obtain insight into the chlamydiae prevalence in Polish dairy cattle.

Material and methods: A screening of chlamydial seroprevalence in dairy cattle was initially performed, followed by Chlamydiaceae- and species-specific real-time qPCR. Vaginal swabs (n = 239) and placenta samples (n = 2) from seropositive animals in 142 herds were collected to detect shedders. The study population consisted of cows (n = 2,780) from dairy herds (n = 1,153) located in all Polish voivodeships.

Results: The true animal prevalence was determined to be 33.3%, while the true herd prevalence was 42.7%. Five groups of Polish voivodeships were identified using appropriate statistical tools, highlighting differences that may arise from various factors impacting the spread of chlamydial infections. The only detected chlamydia species was C. pecorum, the presence of which was confirmed in two herds.

Conclusion: This study revealed that chlamydial infections are commonly present in Polish dairy cattle across the country.